Within the context of the production of blades according to the lost wax casting technique, a model is produced in wax—this being the designation used for all material suitable for this purpose—around which a shell mold is produced in a refractory material. Once the shell mold has hardened, the model is removed by causing the wax to melt. A cavity then exists inside the shell mold, into which the metal will be poured. The part reproducing the form of the model is extracted by shaking out the shell mold.
The model itself is produced in an appropriate mold, the cavity of which defines its form. The wax is injected into the cavity of the mold by means of an injection press. The press permits the injection of wax into the injection channel of the mold via an injection nozzle.
The cavity of the part is formed by at least two cavity elements, which are held firmly together one against the other at the moment of injection of the wax under pressure. For this purpose, the cavity elements are supported individually in cavity blocks that are capable of displacement in relation to one another. It should be noted that the cavity can be formed by more than two elements, although generally these other elements merely perform a complementary role.
According to the prior art cited by the applicant for the production of a blade model of which the general form is elongated in a defined direction between the foot and the head of the blade with an intrados face and an extrados face, the mold is arranged in a horizontal plane, and the cavity in the mold is oriented horizontally. The model is thus injected in a horizontal direction, the intrados face and the extrados face also being oriented horizontally. The handling operations are all manual. The operator opens the mold by manually lifting the upper section of the mold upwards. He then removes the model from the cavity, also manually.
This type of mold exhibits a number of disadvantages.
As a result of its horizontal orientation, the cavity may receive unintentional blows by tools on the part of the operator (screwdrivers, knives, compressed air nozzles) or marks left by equipment which damage it. These marks may then be the subject of costly repairs, which require the tooling to be taken out of service and the production of the parts to be suspended as a result.
The document EP 1216770 proposes a different configuration of the mold for producing a turbine blade in which the cavities mobile in translation are put together horizontally. Their handling, especially for separating then, needs to let them slide on an horizontal support means.
Manual opening because of the weight of the elements may be experienced by the operator as burdensome. In addition, the opening procedure involves numerous operations which, although simple, nevertheless take a lot of time and may adversely affect the quality of the model.
The manual removal of the wax model may give rise to deformation of the latter or may even cause it to break.
The mold contains numerous elements and subcomponents, and a lot of time is required for their design and realization.
The object of the invention is accordingly a mold which overcomes these disadvantages.